The present invention relates to a novel drive mechanism for a body.
Many mass and heat transport systems require establishment of a vibratory oscillational motion on a weighted body. For example, such vibrational displacement may be employed in a plate and frame heat exchanger, a solid liquid mixer, a momentum pump, a gas absorber, and like devices.
Reference is made to my co-pending patent application, Ser. No. 321,797 which describes a device and method for filtering colloidal suspensions employing membranes which are vibrated tangentially to the flow of filtered colloidal materials.
Vibrations have been created using ultrasonic transducers such as those found in U.S. Pat. No. 4,253,962. In fact, it is known that a linear motor can induce back and forth linear oscillations in a body. In general, vibrators or force transducers which produce oscillatory motion on bodies are normally of at least two types; mechanical engines and spring-mass resonators. In the mechanical engine, oscillational motion is produced by an arm attached by a bearing to the rim of a fly wheel. As the fly wheel rotates, the arm oscillates back and forth linearly or orbitally depending on the length and articulation of the tie rod between the load and the crank arm. Reciprocating action thus produced can be used to produce proportional oscillational movement by connecting the arm to a turntable through a bearing. Mechanical engines are generally cumbersome and difficult to control at high frequencies.
The spring-mass resonator utilizes a body to be vibrated which is connected to a spring having a size and thickness which is chosen to create a mechanical resonator with the desired resonant frequency and safe deflection amplitude. For example, a linear mechanical resonator would consist of a compression spring attached to a mass. On the other hand, a torsional mechanical resonator would consist of a mass connected to another, usually larger mass by way of a torsion spring. The larger, mass would receive mechanical energy applied by a force transducer. It should be noted that other vibration mechanisms such as pneumatic vibrators are known in the art. Unfortunately, the creation of precision spring-mass resonators has proven difficult.
A drive mechanism for a body which induces oscillational motion therein with great accuracy and control would be a notable advance in the field of heat and mass transport.